Field of the Invention
The present disclosure relates to a system and a method of controlling fuel supply of a diesel engine. More particularly, it relates to a system and a method of controlling fuel supply of a diesel engine, which set a fuel supply target pressure according to the quantity of fuel consumed by an injector and a temperature of fuel, and adjust revolutions per minute (RPM) for feeding fuel of a low-pressure fuel pump.
Description of Related Art
Most of the fuel injection devices of a diesel vehicle adopt a common rail direct injection system. The common rail direct injection system adopts a method of feeding fuel inside a fuel tank from a low-pressure fuel pump to a high-pressure pump, supplying high-pressure fuel created in the high-pressure pump to a common rail, which is a pressure compression chamber, and injecting high-pressure fuel to an engine by an operation of the injector driven by an electronic automatic device.
The fuel pump mounted in the diesel vehicle includes a low-pressure fuel pump pumping fuel from a fuel tank, and a high-pressure pump pressurizing the fuel pumped by the low-pressure fuel pump at a high pressure.
In order to increase the quantity of fuel injected from the injector in proportion to an RPM of the diesel engine, a discharged pressure of the fuel pump needs to be increased to a predetermined level, and performance of the low-pressure fuel pump demanded by the high-pressure pump is given below.Performance of low-pressure fuel pump (l/hr)=maximum lubricating and cooling performance of high-pressure pump (l/hr)+maximum fuel consumption quantity of engine (l/hr)
As described above, the low-pressure fuel pump always feeds the maximum quantity of fuel to the high-pressure pump considering overload, a high temperature, and the like, which causes an unnecessary and excessive operation of the low-pressure fuel pump while idling, cruise travelling, and decelerated travelling, which occupy most of the travelling, and thus, power consumption is excessively wasted during the operation of the low-pressure fuel pump, thereby deteriorating fuel efficiency, and excessively generating operational noise of the low-pressure fuel pump.
The information disclosed in this Background of the Invention section is only for enhancement of understanding of the general background of the invention and should not be taken as an acknowledgement or any form of suggestion that this information forms the prior art already known to a person skilled in the art.